Found a way:
Goto
.adds\koreader\frontend\apps\reader\modules\reader gesture.lua
Find lines and change 10 to 1 in
highlighted line.
Code:
{_("Back 10 pages"), "page_update_down10", not self.is_docless},
{_("Forward 1 page"), "page_update_up10", not self.is_docless},
{_("Folder up"), "folder_up", self.is_docless},
...
Code:
elseif action == "bookmarks" then
self.ui:handleEvent(Event:new("ShowBookmark"))
elseif action == "page_update_up10" then
self:pageUpdate(1)
elseif action == "page_update_down10" then
self:pageUpdate(-10)
In attachment my config (just remove .txt in the end)